In a communications network, a deployment location of a value-added service device such as a firewall, a load balancer, an intrusion prevention system (IPS), a data loss prevention (DLP) device, an anti-virus (AV) device, or an application acceleration device is usually closely associated with a network topology. That is, the value-added service device is generally deployed in a forwarding path of a service flow that needs to be processed by the value-added service device, or deployed on a network device (such as a router or a switch) in a forwarding path in bypass mode.
When the foregoing deployment manner is used, in each location in which value-added service processing is required, an independent value-added service device needs to be deployed according to a maximum capacity required in the location, which causes a waste of device resources. Furthermore, in the foregoing bypass deployment manner, complicated policy-based routing needs to be configured on the network device, to distribute a service flow that enters the network device to the value-added service device, which increases the burden of configuration, management, and maintenance on the network device.
In addition, there is a solution named value-added service board. In the solution, an independent value-added service board is developed for each type of value-added service, and a corresponding value-added service is implemented by inserting a required value-added service board into a network device. Although this manner can simplify configuration of the network device and reduce burden on the network device, a dedicated value-added service board still needs to be configured for the network device in each location in which value-added service processing is required. Therefore, the problem of a device resource waste still exists. Further, a quantity of addable value-added service boards is limited by a design specification of the network device, and service extension is not flexible enough.
In conclusion, there is no value-added service deployment method that can save device resources and implement flexible service extension.